General Aptitude TestQuantitative ReasoningTrigonometry

If cos(A + B) = 0 and sin(A - B) = 0, then what is the value of angle…

If cos(A + B) = 0 and sin(A - B) = 0, then what is the value of angle A and angle B ? (0 degree < A, B ≤ 90 degree).

Answer & explanation

Correct answer: option 2

We are given :-

cos(A + B) = 0 and sin(A - B) = 0

So, cos(A+B) = sin(A - B)

{ using concept :- Iff A + B = 90º then sinA = cosB }

So, ( A + B ) + ( A - B ) = 90º

2A = 90º

A = 45º

And we know, cos ( A + B ) = 0 Iff ( A + B ) = 90º

So, 45º + B = 90º

B = 45º

Ans :- A = 45º and B = 45º